The present invention relates to recombinant vectors of viral origin and their therapeutic use. More particularly, it relates to recombinant adenoviruses containing a cassette capable of becoming integrated into the genome of the infected cells. The invention also relates to the preparation of these vectors, the pharmaceutical compositions containing them and their use for the transfer of genes in vitro, ex vivo and in vivo, especially within the framework of gene and cell therapies.
Gene and cell therapy consists in correcting a deficiency or an abnormality (mutation, aberrant expression and the like) or in ensuring the expression of a protein of therapeutic interest by the introduction of a genetic information into the cell or the affected organ. This genetic information can be introduced either in vitro into a cell extracted from the organ, the modified cell then being reintroduced into the body, or directly in vivo into the appropriate tissue. Various techniques have been described for the transfer of this genetic information, amongst which are various transfection techniques involving complexes of DNA and DEAE-dextran (Pagano et al., J. Virol. 1 (1967) 891), of DNA and nuclear proteins (Kaneda et al., Science 243 (1989) 375), of DNA and lipids (Felgner et al., PNAS 84 (1987) 7413), of DNA and polylysine, the use of liposomes (Fraley et al., J. Biol. Chem. 255 (1980) 10431) and the like.
More recently, the use of viruses as vectors for the transfer of genes appeared as a promising alternative to these physicochemical transfection techniques. In this respect, various viruses have been tested for their capacity to infect certain cell populations, in particular retroviruses (RSV, HMS, MMS and the like), HSV virus, adeno-associated viruses, and adenoviruses. However, the viral vectors developed up until now do not make it possible to solve satisfactorily all the difficulties linked to the transfer of genes into the cells and/or the body. Thus, adenovirus, which possesses attractive properties for the transfer of genes (possibility of producing high titres, low pathogenicity) is an extrachromosomal virus. Because of this, in dividing cells, the recombinant virus is diluted over generations and eventually disappears completely from the daughter cells. On the other hand, whereas retroviral vectors or vectors derived from adeno-associated viruses (AAV) are capable of becoming integrated into the genome of the cells which they infect, they cannot be produced in large quantities nor for example incorporate large transgenes.